Re: [PATCH v8 1/2] drm/bridge: move bridges_show logic from drm_debugfs.c

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 26 Feb 2025, Luca Ceresoli <luca.ceresoli@bootlin.com> wrote:
> In preparation to expose more info about bridges in debugfs, which will
> require more insight into drm_bridge data structures, move the bridges_show
> code to drm_bridge.c.
>
> Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
> Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
>
> ---
>
> Changed in v8:
>  - add the file in drm_bridge.c, which avois the added #if CONFIG_DEBUG_FS
>
> This patch was added in v7.
> ---
>  drivers/gpu/drm/drm_bridge.c  | 42 ++++++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/drm_debugfs.c | 38 +-------------------------------------
>  include/drm/drm_bridge.h      |  2 ++
>  3 files changed, 45 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
> index 241a384ebce39b4a3db58c208af27960904fc662..a6bf1a565e3c3a8d24de60448972849f6d86ba72 100644
> --- a/drivers/gpu/drm/drm_bridge.c
> +++ b/drivers/gpu/drm/drm_bridge.c
> @@ -21,6 +21,7 @@
>   * DEALINGS IN THE SOFTWARE.
>   */
>  
> +#include <linux/debugfs.h>
>  #include <linux/err.h>
>  #include <linux/media-bus-format.h>
>  #include <linux/module.h>
> @@ -1335,6 +1336,47 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np)
>  EXPORT_SYMBOL(of_drm_find_bridge);
>  #endif
>  
> +static int encoder_bridges_show(struct seq_file *m, void *data)
> +{
> +	struct drm_encoder *encoder = m->private;
> +	struct drm_printer p = drm_seq_file_printer(m);
> +	struct drm_bridge *bridge;
> +	unsigned int idx = 0;
> +
> +	drm_for_each_bridge_in_chain(encoder, bridge) {
> +		drm_printf(&p, "bridge[%u]: %ps\n", idx++, bridge->funcs);
> +		drm_printf(&p, "\ttype: [%d] %s\n",
> +			   bridge->type,
> +			   drm_get_connector_type_name(bridge->type));
> +
> +		if (bridge->of_node)
> +			drm_printf(&p, "\tOF: %pOFfc\n", bridge->of_node);
> +
> +		drm_printf(&p, "\tops: [0x%x]", bridge->ops);
> +		if (bridge->ops & DRM_BRIDGE_OP_DETECT)
> +			drm_puts(&p, " detect");
> +		if (bridge->ops & DRM_BRIDGE_OP_EDID)
> +			drm_puts(&p, " edid");
> +		if (bridge->ops & DRM_BRIDGE_OP_HPD)
> +			drm_puts(&p, " hpd");
> +		if (bridge->ops & DRM_BRIDGE_OP_MODES)
> +			drm_puts(&p, " modes");
> +		if (bridge->ops & DRM_BRIDGE_OP_HDMI)
> +			drm_puts(&p, " hdmi");
> +		drm_puts(&p, "\n");
> +	}
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(encoder_bridges);
> +
> +void drm_bridge_debugfs_encoder_params(struct dentry *root,
> +				       struct drm_encoder *encoder)
> +{
> +	/* bridges list */
> +	debugfs_create_file("bridges", 0444, root, encoder, &encoder_bridges_fops);

The function could look at encoder->debugfs_entry instead of requiring
the root parameter, but that's neither here nor there.

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> +}
> +
>  MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");
>  MODULE_DESCRIPTION("DRM bridge infrastructure");
>  MODULE_LICENSE("GPL and additional rights");
> diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
> index 6b2178864c7ee12db9aa1f562e106b2f604439f8..3dfd8b34dceb7a5b8f11e3072a1eaef430869722 100644
> --- a/drivers/gpu/drm/drm_debugfs.c
> +++ b/drivers/gpu/drm/drm_debugfs.c
> @@ -740,40 +740,6 @@ void drm_debugfs_crtc_remove(struct drm_crtc *crtc)
>  	crtc->debugfs_entry = NULL;
>  }
>  
> -static int bridges_show(struct seq_file *m, void *data)
> -{
> -	struct drm_encoder *encoder = m->private;
> -	struct drm_printer p = drm_seq_file_printer(m);
> -	struct drm_bridge *bridge;
> -	unsigned int idx = 0;
> -
> -	drm_for_each_bridge_in_chain(encoder, bridge) {
> -		drm_printf(&p, "bridge[%u]: %ps\n", idx++, bridge->funcs);
> -		drm_printf(&p, "\ttype: [%d] %s\n",
> -			   bridge->type,
> -			   drm_get_connector_type_name(bridge->type));
> -
> -		if (bridge->of_node)
> -			drm_printf(&p, "\tOF: %pOFfc\n", bridge->of_node);
> -
> -		drm_printf(&p, "\tops: [0x%x]", bridge->ops);
> -		if (bridge->ops & DRM_BRIDGE_OP_DETECT)
> -			drm_puts(&p, " detect");
> -		if (bridge->ops & DRM_BRIDGE_OP_EDID)
> -			drm_puts(&p, " edid");
> -		if (bridge->ops & DRM_BRIDGE_OP_HPD)
> -			drm_puts(&p, " hpd");
> -		if (bridge->ops & DRM_BRIDGE_OP_MODES)
> -			drm_puts(&p, " modes");
> -		if (bridge->ops & DRM_BRIDGE_OP_HDMI)
> -			drm_puts(&p, " hdmi");
> -		drm_puts(&p, "\n");
> -	}
> -
> -	return 0;
> -}
> -DEFINE_SHOW_ATTRIBUTE(bridges);
> -
>  void drm_debugfs_encoder_add(struct drm_encoder *encoder)
>  {
>  	struct drm_minor *minor = encoder->dev->primary;
> @@ -789,9 +755,7 @@ void drm_debugfs_encoder_add(struct drm_encoder *encoder)
>  
>  	encoder->debugfs_entry = root;
>  
> -	/* bridges list */
> -	debugfs_create_file("bridges", 0444, root, encoder,
> -			    &bridges_fops);
> +	drm_bridge_debugfs_encoder_params(root, encoder);
>  
>  	if (encoder->funcs && encoder->funcs->debugfs_init)
>  		encoder->funcs->debugfs_init(encoder, root);
> diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
> index 496dbbd2ad7edff7f091adfbe62de1e33ef0cf07..0890acfe04b99b1ccbbff10b507cb8c2b2705e06 100644
> --- a/include/drm/drm_bridge.h
> +++ b/include/drm/drm_bridge.h
> @@ -1108,4 +1108,6 @@ static inline struct drm_bridge *drmm_of_get_bridge(struct drm_device *drm,
>  }
>  #endif
>  
> +void drm_bridge_debugfs_encoder_params(struct dentry *root, struct drm_encoder *encoder);
> +
>  #endif

-- 
Jani Nikula, Intel